The present invention relates to a cable winding system for such electrically powered vehicles (e.g. LHD machines and dumpers) and working machines which operate in cramped underground conditions like mines and tunnels and which receive their driving power through a flexible cable.
The main principle is to employ a rotating, axially vertical cable winding means, mounted on the center line of a vehicle, and a guide means is disposed at the end of an extension arm journalled concentrically therewith, the moment which effects winding of the cable acts between the extension arm and winding means.
Due to e.g. exhaust gas problems, the present tendency in the field of transport, loading and similar vehicles and machines working in underground conditions is to replace diesel power by electric power. This development has been slowed down by problems, caused by a cable link required between a vehicle and stationary electric mains, e.g. by a restricted operating range, by the short service life of a cable, as well as by a substantial demand for space of a cable drum. The prior art winding systems do not permit satisfactory driving past the cable connection point and, therefore, in a tunnel or passage it is often a must to operate in just one direction from the connection point. This means a double cable length, as compared to the situation where the connection point would be located at the midway point of an operating range.
The prior winding systems employ a vehicle having a rear portion on which is mounted a horizontal drum for winding thereon a cable of circular cross section but the empty interior of such a drum is wasted space. This system requires a lot of space, but the empty interior of such a drum is wasted space. A cable is usually passed on to the drum through a port defined by four crosswise arranged rollers; the port is connected to the rider of a parallel winding means when using a wide drum. Even in the case of straight forward driving the cable falls down into a pattern of wavy lines. The cable extends from a vehicle in straight rearward direction and every change of a driving angle bends a cable by the radius of said port rollers which is inevitably rather small relative to the diameter of a cable. A tolerable mode of driving past the connection point has been attempted by providing the rear corners of a vehicle with tall vertical rollers which steer the cable along the side of a vehicle. For practical reasons, these rollers have also small diameters and damage a cable, and they are not capable of displacing a cable to a safe distance from the side of a vehicle.
Prior known is also a system in which a cable is collected by means of a rotating guide arm within a kind of vertically disposed barrel. The practical application of this system is difficult because of its complicated structure and operating principle leading to twists and tangles in a cable.